Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Other Comprehensive Loss	Retained Earnings
Beginning balance (in shares) at Dec. 31, 2018		16,504,000
Beginning balance at Dec. 31, 2018	$ 160,762	$ 17	$ 256,458	$ (153,900)		$ 58,187
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	21,998		21,998
Issuance of common stock upon exercise of stock option grants (in shares)		34,000
Issuance of common stock upon exercise of stock option grants	260		260
Payment of employee withholding tax upon vesting of stock-based awards	(198)		(198)
Common stock repurchases	(17,961)			(17,961)
Other comprehensive loss	0
Net (loss) income	14,313					14,313
Ending balance (in shares) at Dec. 31, 2019		16,538,000
Ending balance at Dec. 31, 2019	179,174	$ 17	278,518	(171,861)		72,500
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	$ 24,756		24,756
Issuance of common stock upon exercise of stock option grants (in shares)	149,473	149,000
Issuance of common stock upon exercise of stock option grants	$ 3,654		3,654
Payment of employee withholding tax upon vesting of stock-based awards	(1,525)		(1,525)
Issuance of common stock related to vesting of restricted stock (in shares)		52,000
Common stock repurchases	(32,037)			(32,037)
Other comprehensive loss	0
Net (loss) income	11,989					11,989
Ending balance (in shares) at Dec. 31, 2020		16,739,000
Ending balance at Dec. 31, 2020	186,011	$ 17	305,403	(203,898)	$ 0	84,489
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense	$ 19,555		19,555
Issuance of common stock upon exercise of stock option grants (in shares)	122,847	101,000
Issuance of common stock upon exercise of stock option grants	$ 2,398		2,398
Issuance of common stock related to vesting of restricted stock (in shares)		63,000
Issuance of common stock related to vesting of restricted stock	(1,577)		(1,577)
Common stock repurchases	(21,213)			(21,213)
Other comprehensive loss	(94)				(94)
Net (loss) income	(8,627)					(8,627)
Ending balance (in shares) at Dec. 31, 2021		16,903,000
Ending balance at Dec. 31, 2021	$ 176,453	$ 17	$ 325,779	$ (225,111)	$ (94)	$ 75,862